The function dcb_set_attribute() takes a fully-formed payload as an
argument. For callers that need to build a nested attribute, such as is the
case for DCB APP table, this is not great, because with libmnl, they would
need to construct a separate netlink message just to pluck out the payload
and hand it over to this function.
Currently, dcb_set_attribute() also always wraps the payload in an
DCB_ATTR_IEEE container, because that is what all the dcb subtools so far
needed. But that is not appropriate for DCBX in particular, and in fact a
handful other attributes, as well as any CEE payloads.
Instead, generalize this code by adding parameters for constructing a
custom payload and for fetching the response from a custom response
attribute. Then add dcb_set_attribute_va(), which takes a callback to
invoke in the right place for the nest to be built, and
dcb_set_attribute_bare(), which is similar to dcb_set_attribute(), but does
not encapsulate the payload in an IEEE container. Rewrite
dcb_set_attribute() compatibly in terms of the new functions.
Signed-off-by: Petr Machata <m...@pmachata.org>
---
dcb/dcb.c | 99 ++++++++++++++++++++++++++++++++++++++++++++++++++-----
dcb/dcb.h | 7 ++++
2 files changed, 98 insertions(+), 8 deletions(-)
diff --git a/dcb/dcb.c b/dcb/dcb.c
index 6640deef5688..9bbbbfa74619 100644
--- a/dcb/dcb.c
+++ b/dcb/dcb.c
@@ -94,12 +94,17 @@ static int dcb_get_attribute_cb(const struct nlmsghdr *nlh,
void *data)
return mnl_attr_parse(nlh, sizeof(struct dcbmsg),
dcb_get_attribute_attr_cb, data);
}
+struct dcb_set_attribute_response {
+ int response_attr;
+};
+
static int dcb_set_attribute_attr_cb(const struct nlattr *attr, void *data)
{
+ struct dcb_set_attribute_response *resp = data;
uint16_t len;
uint8_t err;
- if (mnl_attr_get_type(attr) != DCB_ATTR_IEEE)
+ if (mnl_attr_get_type(attr) != resp->response_attr)
return MNL_CB_OK;
len = mnl_attr_get_payload_len(attr);
@@ -172,19 +177,23 @@ int dcb_get_attribute(struct dcb *dcb, const char *dev,
int attr, void *data, si
return 0;
}
-int dcb_set_attribute(struct dcb *dcb, const char *dev, int attr, const void
*data, size_t data_len)
+static int __dcb_set_attribute(struct dcb *dcb, int command, const char *dev,
+ int (*cb)(struct dcb *, struct nlmsghdr *, void
*),
+ void *data, int response_attr)
{
+ struct dcb_set_attribute_response resp = {
+ .response_attr = response_attr,
+ };
struct nlmsghdr *nlh;
- struct nlattr *nest;
int ret;
- nlh = dcb_prepare(dcb, dev, RTM_SETDCB, DCB_CMD_IEEE_SET);
+ nlh = dcb_prepare(dcb, dev, RTM_SETDCB, command);
- nest = mnl_attr_nest_start(nlh, DCB_ATTR_IEEE);
- mnl_attr_put(nlh, attr, data_len, data);
- mnl_attr_nest_end(nlh, nest);
+ ret = cb(dcb, nlh, data);
+ if (ret)
+ return ret;
- ret = dcb_talk(dcb, nlh, dcb_set_attribute_cb, NULL);
+ ret = dcb_talk(dcb, nlh, dcb_set_attribute_cb, &resp);
if (ret) {
perror("Attribute write");
return ret;
@@ -192,6 +201,80 @@ int dcb_set_attribute(struct dcb *dcb, const char *dev,
int attr, const void *da
return 0;
}
+struct dcb_set_attribute_ieee_cb {
+ int (*cb)(struct dcb *dcb, struct nlmsghdr *nlh, void *data);
+ void *data;
+};
+
+static int dcb_set_attribute_ieee_cb(struct dcb *dcb, struct nlmsghdr *nlh,
void *data)
+{
+ struct dcb_set_attribute_ieee_cb *ieee_data = data;
+ struct nlattr *nest;
+ int ret;
+
+ nest = mnl_attr_nest_start(nlh, DCB_ATTR_IEEE);
+ ret = ieee_data->cb(dcb, nlh, ieee_data->data);
+ if (ret)
+ return ret;
+ mnl_attr_nest_end(nlh, nest);
+
+ return 0;
+}
+
+int dcb_set_attribute_va(struct dcb *dcb, int command, const char *dev,
+ int (*cb)(struct dcb *dcb, struct nlmsghdr *nlh, void
*data),
+ void *data)
+{
+ struct dcb_set_attribute_ieee_cb ieee_data = {
+ .cb = cb,
+ .data = data,
+ };
+
+ return __dcb_set_attribute(dcb, command, dev,
+ &dcb_set_attribute_ieee_cb, &ieee_data,
+ DCB_ATTR_IEEE);
+}
+
+struct dcb_set_attribute {
+ int attr;
+ const void *data;
+ size_t data_len;
+};
+
+static int dcb_set_attribute_put(struct dcb *dcb, struct nlmsghdr *nlh, void
*data)
+{
+ struct dcb_set_attribute *dsa = data;
+
+ mnl_attr_put(nlh, dsa->attr, dsa->data_len, dsa->data);
+ return 0;
+}
+
+int dcb_set_attribute(struct dcb *dcb, const char *dev, int attr, const void
*data, size_t data_len)
+{
+ struct dcb_set_attribute dsa = {
+ .attr = attr,
+ .data = data,
+ .data_len = data_len,
+ };
+
+ return dcb_set_attribute_va(dcb, DCB_CMD_IEEE_SET, dev,
+ &dcb_set_attribute_put, &dsa);
+}
+
+int dcb_set_attribute_bare(struct dcb *dcb, int command, const char *dev,
+ int attr, const void *data, size_t data_len,
+ int response_attr)
+{
+ struct dcb_set_attribute dsa = {
+ .attr = attr,
+ .data = data,
+ .data_len = data_len,
+ };
+
+ return __dcb_set_attribute(dcb, command, dev,
+ &dcb_set_attribute_put, &dsa, response_attr);
+}
+
void dcb_print_array_u8(const __u8 *array, size_t size)
{
SPRINT_BUF(b);
diff --git a/dcb/dcb.h b/dcb/dcb.h
index 388a4204b95c..da14937c8925 100644
--- a/dcb/dcb.h
+++ b/dcb/dcb.h
@@ -2,6 +2,7 @@
#ifndef __DCB_H__
#define __DCB_H__ 1
+#include <libmnl/libmnl.h>
#include <stdbool.h>
#include <stddef.h>
@@ -32,6 +33,12 @@ int dcb_get_attribute(struct dcb *dcb, const char *dev, int
attr,
void *data, size_t data_len);
int dcb_set_attribute(struct dcb *dcb, const char *dev, int attr,
const void *data, size_t data_len);
+int dcb_set_attribute_va(struct dcb *dcb, int command, const char *dev,
+ int (*cb)(struct dcb *dcb, struct nlmsghdr *nlh, void
*data),
+ void *data);
+int dcb_set_attribute_bare(struct dcb *dcb, int command, const char *dev,
+ int attr, const void *data, size_t data_len,
+ int response_attr);
void dcb_print_named_array(const char *json_name, const char *fp_name,
const __u8 *array, size_t size,
--
2.26.2
